December weather forecast
Williamstown, WV

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Weather in December

December witnesses a significant drop in temperatures, tumbling to the frigid range of 30.4°F (-0.9°C) to 41.7°F (5.4°C). Snowfall makes a comeback with an average accumulation of 1.46" (37mm). The decrease in daylight hours to 9.4, the shortest in the year, indicates the arrival of winter. In addition, atmospheric pressure reaches 30.13" (765mm), one of the highest readings of the year. As the year wraps up, anticipation for the New Year's weather commences.

Temperature

In Williamstown, entering December brings a temperature decrement, reducing from November's fresh 51.1°F (10.6°C) to a wintry 41.7°F (5.4°C). Williamstown's nights in December cool down to an average low-temperature of 30.4°F (-0.9°C).

Humidity

In December, the average relative humidity in Williamstown is 82%.

Rainfall

In Williamstown, West Virginia, in December, it is raining for 11.3 days, with typically 2.24" (57mm) of accumulated precipitation. In Williamstown, during the entire year, the rain falls for 156.1 days and collects up to 24.8" (630mm) of precipitation.

Snowfall

January through April, October through December are months with snowfall. In December, in Williamstown, it is snowing for 5.4 days. Throughout December, 1.46" (37mm) of snow is accumulated. Throughout the year, there are 31.3 snowfall days, and 9.37" (238mm) of snow is accumulated.

Daylight

December has the shortest days of the year, with an average of 9h and 24min of daylight.
On the first day of the month, sunrise is at 7:27 am and sunset at 5:02 pm. On the last day of December, in Williamstown, sunrise is at 7:45 am and sunset at 5:12 pm EST.

Sunshine

In Williamstown, West Virginia, the average sunshine in December is 3.8h.

UV index

January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index in Williamstown. A UV Index estimate of 2, and below, represents a low health risk from exposure to the Sun's UV radiation for the average person.
Note: In December, a daily UV index of 2 turns into the following recommendations:
Extended time in the sun generally does not harm most, but those with sensitive skin, infants, and children should always be protected. Around midday, solar radiation is most harmful; hence, exposure should be limited. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense. Take warning! The intensity of the Sun's UV radiation can be nearly amplified twice due to snow reflection.
Updated: Feb 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

Is December cold in Williamstown?

During December, Williamstown experiences an average high-temperature of 41.7°F (5.4°C) and a low-temperature of 30.4°F (-0.9°C). The average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which combines air temperature and relative humidity, in August is computed to be 93.2°F (34°C).

What is the average humidity in December in Williamstown?

The average relative humidity in December in Williamstown, West Virginia, is 82%.

How much does it rain in Williamstown in December?

In Williamstown, West Virginia, during December, the rain falls for 11.3 days and regularly aggregates up to 2.24" (57mm) of precipitation.

How much does it snow in Williamstown in December?

In Williamstown, West Virginia, in December, snow falls for 5.4 days, with typically accumulated 1.46" (37mm) of snow.

What is the month with the shortest days in Williamstown?

With an average of 9h and 24min of daylight, December has the shortest days of the year in Williamstown.

How many hours of daylight does Williamstown have in December?

The average day length in December is 9h and 27min.

When is the sunrise / sunset in December in Williamstown?

On the first day of December in Williamstown, sunrise is at 7:27 am and sunset at 5:02 pm. On the last day of the month, sunrise is at 7:45 am and sunset at 5:12 pm EST.

How long on average sun shines in December in Williamstown?

In Williamstown, West Virginia, the average sunshine duration in December is 3.8h.

When is the lowest UV index in Williamstown?

The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2.

How high is the UV index in December in Williamstown?

In December, the average daily maximum UV index in Williamstown is 2. A UV Index estimate of 2, and below, represents a minimal health vulnerability from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Williamstown, WV

Average temperature in December - Williamstown, WV
  • Average high temperature in December: 41.7°F

The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (36.1°F).

  • Average low temperature in December: 30.4°F

The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (22.8°F).

Average pressure in December
Williamstown, WV

Average pressure in December - Williamstown, WV
  • Average pressure in December: 30.13"Hg

The month with the highest atmospheric pressure is November (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.96"Hg).

Average wind speed in December
Williamstown, WV

Average wind speed in December - Williamstown, WV
  • Average wind speed in December: 6.2mph

The windiest month (with the highest average wind speed) is February (6.8mph).
The calmest month (with the lowest average wind speed) is August (4.2mph).

Average humidity in December
Williamstown, WV

Average humidity in December - Williamstown, WV
  • Average humidity in December: 82%

The months with the highest relative humidity are January and February (83%).
The months with the lowest relative humidity are June, July and August (76%).

Average rainfall in December
Williamstown, WV

Average rainfall in December - Williamstown, WV
  • Average rainfall in December: 2.24"

The wettest month (with the highest rainfall) is May (3.19").
The driest month (with the least rainfall) is September (1.46").

Average rainfall days in December
Williamstown, WV

Average rainfall days in December - Williamstown, WV
  • Average rainfall days in December: 11.3 days

The month with the highest number of rainy days is May (18.3 days).
The month with the least rainy days is November (8.4 days).

Average snowfall in December
Williamstown, WV

Average snowfall in December - Williamstown, WV
  • Average snowfall in December: 1.46"

The month with the highest snowfall is February (2.8").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Williamstown, WV

Average snowfall days in December - Williamstown, WV
  • Average snowfall days in December: 5.4 days

The month with the highest number of snowfall days is January (9.5 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Williamstown, WV

Average daylight in December / Average sunshine in December - Williamstown, WV
  • Average daylight in December: 9h and 2min

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).

  • Average sunshine in December: 3h and 5min

The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 24min).

Average sunshine days in December
Williamstown, WV

Average sunshine days in December - Williamstown, WV
  • Average sunshine days in December: 15.8 days

The month with the most sunshine days is November (19.9 days).
The month with the least sunshine days is May (9.8 days).

Average UV index in December
Williamstown, WV

Average UV index in December - Williamstown, WV
  • Average UV index in December: 2

The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in December
Williamstown, WV

Average cloud cover in December - Williamstown, WV
  • Average cloud cover in December: 61

The month with the most cloud cover is January (Cloud cover 64).
The month with the least cloud cover is August (Cloud cover 34).

Average visibility in December
Williamstown, WV

Average visibility in December - Williamstown, WV
  • Average visibility in December: 5mi

The months with the highest visibility are April and November (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August, September, October and December (5mi).

Williamstown, West Virginia, USA

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